The present invention relates in general to sewing machines and in particular to a new and useful guide device for guiding workpieces to be sewn by a sewing machine, the guide device including at least one guide wheel which is rotatably mounted on a rocker for movement into and out of engagement with the workpiece.
A guide device having a guide wheel is disclosed in U.S. Pat. No. 4,292,908. For guiding work consisting of two plies of cloth, this guide device has an upper and a lower guide wheel. Both guide wheels carry on the circumference of the wheel bodies, a plurality of freely rotatable rollers arranged crosswise to the wheel plane. The guide wheels are mounted on a support in the form of a pivotable arm, on which also a belt drive is arranged which connects the guide wheel to a motor attached to the support.
Since, due to the mutual distance of the rollers, the guide wheels have an out-of-round polygon-like circumference, the supports are alternately slightly lowered and raised as the guide wheels roll on and off the work. Superimposed on these movements may be vibrations caused by the sewing machine, so that at certain sewing and control speeds the supports execute uncontrolled swinging motions which impair the aligning action of the guide device.